DeniliquinDeniliquin

Effluent Disposal Project Effluent Disposal Project

Land Resource, Irrigation Land Resource, Irrigation

and Enterprise Options and Enterprise Options

Peter ClinnickPeter Clinnick

Advanced Environmental Systems Pty LtdAdvanced Environmental Systems Pty LtdCreating a Sustainable FutureCreating a Sustainable Future

Tel (03) 5482 5882 Email: Tel (03) 5482 5882 Email: AES@Echuca.net.auAES@Echuca.net.au

The key management considerations were:• Flooding• Soil sodicity• Nutrient loading• Soil and wastewater salinity impacts• Leaching and drainage management• Hydraulic loading and watertable impacts• Winter storage volumes and seasonal water use

•A landlocked depression dominates the centre of the site

Methods

SOILSRed brown earth and (Sodosol) Deniboota sandy loam/loam

-Highest elevations and midslopes.Transitional Red brown earth (Sodosol) Marah clay loam

- Mid and lower slopes. Non self mulching clay (Vertosol) Riverina clay

-Drainage depressions.

Site No 62 64 65 66 69 78 80.0 84.0 85 ECe (dS/m)

(0-10 cm) 5.46 0.90 0.74 1.67 1.98 1.41 1.04 0.52 0.58 ECe (dS/m)

(10-40 cm) 5.67 6.01 3.08 10.26 6.05 13.50 0.31 1.06 7.65

Salinity

0.668 dS/m wastewater

Sodicity in the root zone

Site No 62 64 65 66 69 78 80.0 84.0 85 ESP % 0-10cm 17.40 8.30 0.70 18.70 0.71 16.40 6.50 11.20 8.40 ESP %

~10-40cm 25.80 21.60 3.08 36.30 3.04 22.80 5.90 7.95 33.10

Effects of sodicity and compaction

Controlled traffic

• Lasered furrow irrigation is the preferred option in this instance

• Some land (laser) grading may be required before furrows can be constructed

• It is important for plant productivity that the extent of land grading be minimised

The system advantage : • It is compatible with controlled traffic management • Less capital intensive than dripper or sprinkler systems

Economic: High establishment costs and low returns c. f. irrigated crops. Unsecured sales. Social: Non identified. Environmental: Low fire risk Insect attack. Carbon emissions in harvesting.

Economic: Substitute for agricultural production. Social: Flow-on employment with value adding. Environmental: Expensive set-up cost (`$8,000 per ha) Rapid growth rates.

Estab $6-10,000GM $700-1,000

ha/yr

Farm forestry

(Irrigated)

Economic:

Waterlogging losses in wet years. Social: Non identified.Environmental: Carbon emissions in harvesting.

Economic: Opportunities for value adding, summer feed possibilities. Good markets close-by.Social: Employment in value adding activities Assists in maintaining demographics.Environmental: Almost full use of applied water.

Estab 800-3,000(Crop only$ 250-300)

GM~ $2,450/ha

Lucerne

(Irrigated)

Other costs and

disadvantages

Benefits and advantagesEstablishment

cost and gross

margin (per ha)

Enterprise Option

Enterprise Options

Economic: None identified.Social: Low labour

requirement.Environmental: Fire

damage/loss. Insect attack. Carbon emissions in harvesting.

Economic: Excellent gross margins.Social: Flow-on employment.

Maintains demographics. Environmental: Periodic labour

inputs.

Estab $3,000GM ~$3-30,000Years 4-51-2 kg/ha =>$2-3,000Years 10=> 10 kg/ha

$2-3,000/kg=$30,000/ha

Forestry / horticultural

seed orchard

(Irrigated)

Economic: Skills need to be acquired or purchased.

Social: Non identified.Environmental: Risk of fire

or insect attack.

Economic: Good GM’s if well managed and marketed.

Social: Flow-on employment Maintains demographics.

Environmental: Improves water balance.

Estab $6-10,000GM $10-20,000

Cut foliage

(predominantly

eucalypts

Irrigated)

Other costs and

disadvantages

Benefits and advantagesEstablishment cost

and gross margin

(per ha)

Enterprise Option

Other crops considered• Plums - Soil too sodic waterlogging in

winter, irrigation problems unless soil is well managed

• Olives – Could grow, but not likely to be an economic yield

• Grapes - ditto

Rec 11. Root zone sodicity requires close monitoring some leaching,

balance with watertable.

Rec 12. Irrigation control in line with associated drainage requirements

Rec 13. Deep ripping and mounding and substantial gypsum application 30T/ha

Rec 14. Nitrogen (N) (0-10 cm) depleted: Requirement for N of 20kg/ha.

Similarly, phosphorus requirements from 10-18 kg/ha.

Rec 15. Essential micronutrients depleted

Cu 0.5-1.5 kg/ha, Zn 3.75 kg/ha, Mo 0.025 kg/ha, Mn 0.5-1.5 kg/ha.

Rec 16. Subsurface drainage and serial biological disposal systems required

in the future if salinity / watertable levels increase

Rec 17. Green manure crops for several years to build up soil organic matter

Soil Mapping & Land Capability

Water & Wastewater (EPA Approvals)

Flora and Fauna Surveys

Environmental Impact Assessments

Cultural Heritage Management Plans

Energy Assessments & Carbon Accounting

(03) 5482 5882pc@environmentalsystems.com.au